Renal cell carcinoma is a malignant tumour that develops from the cells of the kidney tissue itself — not to be confused with urothelial carcinoma of the renal pelvis or ureter, which develops from the lining of the urinary tract and is diagnosed and treated differently. In Switzerland, around 1,200 people develop kidney cancer every year, with renal cell carcinoma accounting for about 85 to 90% of malignant kidney tumours; around two-thirds of those affected are men. The disease occurs mainly in older age — almost half of patients are 70 or older at diagnosis — and around 300 people die from it in Switzerland each year.
Often an incidental finding
Small kidney tumours usually cause no symptoms and are therefore often discovered incidentally today during an ultrasound, a CT scan or an MRI carried out for another reason. Thanks to modern imaging, many kidney tumours are now detected at an early, readily treatable stage.
A more advanced kidney tumour, on the other hand, can present with visible or invisible blood in the urine, persistent flank pain, a palpable mass in the abdomen or flank, unintentional weight loss, marked fatigue, recurring fever or night sweats, or anaemia or other abnormal lab values. These symptoms can have many other causes, but visible blood in the urine should always be assessed by a urologist promptly.
Risk factors
The precise cause of renal cell carcinoma usually cannot be determined in an individual case. The most important modifiable risk factors include smoking, significant excess weight, high blood pressure, and lack of exercise together with the metabolic conditions associated with it. Other risk factors include chronically impaired kidney function, long-term dialysis, acquired cystic kidney disease in chronic kidney failure, a family history of kidney cancer, and rare hereditary tumour syndromes such as von Hippel-Lindau syndrome. Genetic counselling can be worthwhile in particular for disease at a young age, bilateral or multiple kidney tumours, or a notable family history.
Diagnosis
If an ultrasound reveals an unclear kidney mass, further contrast-enhanced imaging is usually carried out: depending on the individual situation, this may include a contrast-enhanced CT scan of the abdomen, an MRI of the kidney, chest imaging, a kidney function check, a blood count with liver values and other laboratory tests, or an ultrasound of the kidneys and urinary tract. Imaging allows an assessment of the tumour's size, location and blood supply, as well as its relationship to the renal vessels, renal pelvis and surrounding organs. Not every kidney mass is malignant — particularly with small kidney tumours, it may also be a benign oncocytoma, an angiomyolipoma, or a complex renal cyst.
Is a kidney tumour biopsy necessary? A tissue sample is usually not necessary before kidney surgery, as MRI in particular has made enormous progress in recent years. A targeted biopsy before surgery can, however, be worthwhile in cases of unclear imaging, before local ablative treatment or drug-based tumour therapy, when active surveillance is planned and the result would influence the decision, or when a metastasis or another tumour disease is suspected. Before thermal ablation, the diagnosis should be confirmed by a prior percutaneous biopsy.
Treatment of localised renal cell carcinoma
Treatment depends not only on tumour size, but equally on its exact location, its relationship to the vessels and renal pelvis, kidney function, age, coexisting conditions and the personal wishes of the person affected.
Kidney-preserving tumour removal. For small, technically suitable tumours, partial nephrectomy is the treatment of choice: the tumour is removed while preserving as much healthy kidney tissue as possible. The operation can be performed openly, laparoscopically or robot-assisted; robot-assisted partial nephrectomy allows precise removal of the tumour and subsequent reconstruction of the kidney through small skin incisions. Preserving healthy kidney tissue is especially important with impaired kidney function, a solitary kidney, bilateral kidney tumours, an increased risk of later kidney disease, or in younger patients. For localised tumours up to seven centimetres, partial nephrectomy is the goal, provided it is technically feasible and oncologically safe.
Complete removal of the kidney. For larger, centrally located or locally advanced tumours, an organ-preserving operation may not be technically sensible or oncologically safe. In these cases, a radical nephrectomy is performed — the complete removal of the affected kidney — carried out laparoscopically, robot-assisted or openly depending on the findings. The adrenal gland and regional lymph nodes are not routinely removed as well; removal is carried out specifically when imaging or surgical findings suggest tumour involvement.
Active surveillance. Not every small kidney tumour needs to be treated immediately. Particularly in older patients, those with significant coexisting conditions, or limited life expectancy, active surveillance can be appropriate: the tumour is monitored regularly with ultrasound, CT or MRI, and treatment is started if the tumour grows significantly or other signs of progression appear. This strategy can be considered especially for small tumours up to four centimetres, where the risk of treatment is greater than the immediate danger posed by the tumour. Active surveillance does not mean ignoring the finding — it is a deliberately chosen treatment strategy with defined follow-up intervals.
Local ablative treatment. For small kidney tumours, image-guided local tumour destruction via interventional radiology can be carried out in selected situations: cryoablation (destruction through controlled freezing), radiofrequency ablation (destruction through heat), or microwave ablation (heat generation through electromagnetic energy). Treatment is usually performed percutaneously: under CT or ultrasound guidance, a special probe is advanced through the skin into the tumour. Ablation is considered in particular for small tumours and for patients for whom surgery would carry an increased risk due to age, coexisting conditions or impaired kidney function. Because long-term data are less extensive than for surgical partial nephrectomy, and the risk of incomplete treatment increases with tumour size, radiofrequency ablation is not routinely recommended for tumours over three centimetres, nor cryoablation for tumours over four centimetres.
Stereotactic body radiotherapy (SBRT/SABR). Stereotactic body radiotherapy can deliver a high radiation dose to the tumour with millimetre precision, from outside the body, in one or a few sessions, without surgery or probe insertion, while sparing the surrounding healthy tissue as much as possible. It is considered mainly for older or multimorbid patients with a localised kidney tumour requiring treatment, in whom neither surgery nor cryo- or radiofrequency ablation is possible or advisable. As long-term comparative data against partial nephrectomy and thermal ablation techniques remain limited, SBRT is not currently used as standard treatment for all kidney tumours; the decision is made individually, preferably in an interdisciplinary tumour board.
Additional treatment after surgery. For most small, completely removed renal cell carcinomas, no additional drug treatment is needed. For clear cell renal cell carcinoma with an increased risk of recurrence, a time-limited course of immunotherapy with pembrolizumab may be considered after surgery — factors such as tumour stage, grade of differentiation, lymph node status and other histological risk factors are decisive. The potential benefit, the risk of overtreatment, and immune-related side effects are discussed individually; the decision is usually made in an interdisciplinary tumour board.
Advanced renal cell carcinoma and prognosis
If the disease has spread beyond the kidney, effective modern systemic therapies are available today: combinations of different immune checkpoint inhibitors, combinations of immunotherapy and targeted tyrosine kinase inhibitors, targeted drug therapies, and local treatment of individual metastases through surgery, ablation or stereotactic radiotherapy. Classic chemotherapy plays no role in renal cell carcinoma. Treatment depends on the tumour's histological type, the extent of the disease, general health, and individual risk group.
Prognosis depends crucially on the stage at which the disease is detected. If the tumour is confined to the kidney and can be completely removed, long-term chances of a cure are very good. With metastatic disease, a lasting cure is less often possible, though modern immunotherapies and targeted drugs have markedly improved treatment options and prognosis in recent years.
Follow-up care
Follow-up care depends on tumour stage, histological findings, the treatment chosen and individual risk of recurrence. It can include clinical check-ups, monitoring of kidney function and blood pressure, laboratory tests, CT or MRI scans of the abdomen, chest imaging, monitoring of the remaining or partially operated kidney, and joint care with a nephrologist where kidney function is impaired. For small tumours with a low risk of recurrence, less intensive check-ups are needed; for aggressive or locally advanced tumours, closer, longer-term follow-up is carried out. Alongside early detection of a recurrence, preserving kidney function in the long term is an essential goal.
Our aim is to combine oncologically safe treatment with the best possible preservation of kidney function and quality of life. Where surgery, interventional radiology, radiotherapy or drug-based tumour therapy is needed, we coordinate the interdisciplinary care and remain your personal urological point of contact throughout treatment and long-term follow-up.